This competitive renewal award application requests continued funding for the Tinnitus Retraining Therapy Trial (TRTT), a multi-center phase III placebo-controlled randomized trial designed to investigate the efficacy of tinnitus retraining therapy (TRT) and its component parts, directive counseling (DC) and sound therapy (ST). The TRTT is enrolling individuals with subjective debilitating tinnitus to one of 3 treatment groups: () DC and ST achieved with conventional sound generators (SG); (2) DC and placebo SG; (3) Standard-of-care (SC) as usually administered in the military. As of September 1, 2014 the TRTT has recruited 136 of the expected total of 228 participants; 76 participants will be recruited per treatment group using an allocation ratio of 1:1:1. A standardized protocol for treatment and data collection is being used by all centers. The primary outcome is change in Tinnitus Questionnaire (TQ) score assessed longitudinally at follow-up, taking place at 3, 6, 12, and 18 months following the initial treatment session. Secondary outcomes include change in TQ sub-scores, in Tinnitus Handicap Inventory and Tinnitus Functional Index scores, and in the visual analogue scale of the TRT Interview. Other secondary outcomes include audiometric measures, psychoacoustic measures, and change in quality of life. The primary objective of the study is to evaluate the efficacy of TRT (DC and conventional SG) compared with SC. The secondary objectives are to evaluate (1) the efficacy of DC plus placebo SG versus SC, and (2) the efficacy of conventional versus placebo SG in study participants assigned to DC. We hypothesize that (1) full TRT will be more efficacious than SC, (2) DC + placebo SG will be more efficacious than SC , and (3) conventional SG will be more efficacious than placebo SG, in habituating the tinnitus awareness, annoyance, and impact on the study participant's life. Study centers will include a Study Chair's Office, Data Coordinating Center, and Clinical Centers housed in U.S. Army, Navy and Air Force military hospitals. Results from the TRTT are anticipated to impact the clinical practice for severe debilitating tinnitus.